Isis on the march: the Islamic State’s leader has called on followers to kill ‘disbelievers’ in countries including Australia, France, Canada and the US.
Photograph: Uncredited/AP

A video address by the spokesman for the Islamic State (Isis) calling for members to kill civilians and soldiers in countries including Australia has divided opinion among terrorism experts.

The video address and a written English translation attributed to Abu Muhammad al-Adnani was released on Monday, called for members to take retribution against the coalition of countries heading to northern Iraq and Syria to fight them, specifically instructing members to kill – without question and by any means necessary – civilians and soldiers in countries including Australia, France, Canada and the US.

It is the first release from al-Adnani since his June declaration of the establishment of a caliphate and that Isis would be known as Islamic State.

“If you can kill a disbelieving American or European – especially the spiteful and filthy French – or an Australian, or a Canadian, or any other disbeliever from the disbelievers waging war, including the citizens of the countries that entered into a coalition against the Islamic State, then rely upon Allah, and kill him in any manner or way however it may be,” said al-Adnani.

“Do not ask for anyone’s advice and do not seek anyone’s verdict. Kill the disbeliever whether he is civilian or military, for they have the same ruling. Both of them are disbelievers.”

The video comes just days after the largest counter-terrorism raids in Australian history, with police arresting 15 individuals over an alleged plot to commit an act of terrorism. Last week Australia committed a 600-strong military force to the US-led coalition of more than 40 countries and the air strike campaign against Isis. While the prime minister, Tony Abbott, said there would be no boots on the ground in Iraq, he left open the possibility that the mission could extend into combat operations.

The Isis video has divided opinion among terrorism experts.

A Monash University professor, Greg Barton, said the release was “significant” and speaks to a shift in Isis’s operations.

Until now the group has waged a “careful, long-term military campaign” focused on consolidating strength in Iraq and the Syrian civil war.

“Al-Adnani doesn’t make these official statements very often,” Barton told Guardian Australia.

“They’re lengthy, they’re very eloquent, they’re couched very much as fatwa. They’re not just a normal press release, they’re an inspiring call to join together in action, and they have the sort of tone of religious authority.”

Barton said the speech indicated that Isis appeared to be trying to go in the same direction as al-Qaida in encouraging home grown extremism.

“This is the first official statement that now is the time for their foreign fighter community, their support base and and anyone who’s listening to them to take on not just the military coalition in Iraq and Syria but also also where they come from, at their source,” he said.

However Dr Justin Hastings, from the University of Sydney, said the video was actually a sign of weakness.

“It indicates they can’t actually do this themselves so they really have to inspire somebody on the ground to do it for them,” Hastings told Guardian Australia.

The call to arms was a “logical progression” for Isis, which seems to be following al-Qaida’s playbook pretty closely, he said.

“That they would do this now is not really surprising,” he said.

Hastings attributed the heavy domestic coverage, as opposed to the minimal attention it received in other countries, to recent terrorism-related new stories and events in Australia.

“In other countries because we haven’t had a lot of those things happening, it’s going to get less attention.

“The issue’s been at the fore in Australia for a while because of the impression, rightly or wrongly, that Australia has been an unusually high supplier of foreign fighters to Isis and the Middle East in this conflict. Empirically it’s impossible to say if that’s true or not, but it’s the impression people have.”

Rodger Shanahan, non-resident fellow at the Lowy Institute for International Policy and a former army officer, told Guardian Australia the video was “not earth shattering”, as Al-Adnani has been saying this sort of thing for years, but the specific mention of Australia had caught the media’s eye.

“My view is that if you give these people oxygen it encourages them to do it more often, that’s the whole point,” said Shanahan.

“It’s a pretty good debate to have: if this had not been widely reported, would it really have amounted to anything other than security agencies noting Australia being mentioned specifically by the IS spokesperson?”

“But if you go back over the last couple of speeches there are general references to the west, the europeans, the Christians. There’s no change of direction at all. It’s just a continuation of what he’s put out there, but nobody has paid particular attention to it in the past.”

Shanahan said that while security agencies have to take it seriously, anyone who might pay attention to the message in the video is already thinking that way.

“The utility of it in terms of attracting more recruits, I don’t think it’s of utility at all. In terms of interest because it mentions us and Canada and France, yes, it’s interesting, but it’s not an earth shattering thing.”

Clive Williams, an adjunct professor at Macquarie University’s Centre for policing, intelligence, and counter terrorism, told Guardian Australia the call to action was significant for sympathisers in coalition countries, “particularly those that are committing military forces”.

“Al-Qaida had made similar calls for action close to home, but were less specific about what sympathisers should do, and were more controlling in terms of legitimising attacks,” said Williams.

“Islamic State has given its followers a range of low-tech options and simply urged them to get on with it. The options have the potential for creating violent small-scale incidents and a backlash against the Muslim community, which would be playing into Islamic State’s hands.”

Williams said the timing of the statement and the specific mention of Australia “could not have been better” amid government attempts to toughen up security measures.

“Polls here seem to indicate majority public support for Abbott’s no-nonsense approach.”

The federal government is in talks this week looking at amendments to proposed counter-terrorism laws. Abbott signalled on Monday that there would be increased pressure on Australian citizens and that some freedoms would have to be curtailed to ensure people’s safety.

“The delicate balance between freedom and security may have to shift,” said Abbott. “There may be more restrictions on some, so that there can be more protection for others.”